Ppt Gsm Technology by hcg20920

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									    GSM Fundamental



           By
           Uke Kurniawan Usman




1                 Uke Kurniawan Usman - 2005
    Agenda

       Network Architecture
       Functional Layer of GSM
       Air Interface
       System Capacity
       Anti Interference Technology
       Network Planning
       Numbering arrangement

2                                      Uke Kurniawan Usman - 2005
                GSM Network Structure

                                     OMC



                                                      MSC/VLR

                     BSC
                                                      E
                    BIE
                     Abi         A                                 PSTN
              BTS    s                 MSC/VLR                    ISDN
                           BSS                                    PSPDN

                                        C
         Um                                      F          H
                                     HLR/
                                     AUC        EIR       SC/VM
    MS

                                                           MSS




3                                           Uke Kurniawan Usman - 2005
               Mobile Station
                  ( MS )
    Equipment used by mobile service subscribers for
      access to services.




    Mobile Equipment
    Subscriber Identity Module (SIM)
       Mobile stations are not fixed to one subscriber.
       A subscriber is identified with the SIM card.




4                                 Uke Kurniawan Usman - 2005
                       GSM Network Entity
                   Base Transceiver Station
                           ( BTS )



                Base Transceiver Station (BTS)

                   Wireless transmission
                   Wireless diversity
                   Wireless channel encryption
                   Conversion between wired and wireless signals
                   Frequency Hopping

    BaseBand Unit:
     voice and data speed adapting and channel coding
    RF Unit:
     modulating/demodulating, transmitter and receiver
    Common Control Unit:
     BTS operation and maintenance
5                                                Uke Kurniawan Usman - 2005
                       GSM Network Entity
                   Base Station Controller
                          ( BSC )



    Managing Wireless network-BSS
    Monitoring BTS

    Controls:
       Wireless link distribution between MS and BTS
       Communication connection and disconnection
       MS location, handover and paging
       Voice encoding, transecoding (TC), rate, adaptation,
       The operation and maintenance functions of BSS.

6                                               Uke Kurniawan Usman - 2005
                      GSM Network Entity
          Mobile Service Switching Center
                      ( MSC )




    holds all the switching functions
    manages the necessary radio resources,
          updating the location registration
          carrying out the inter-BSC and inter-MSC tender


    Inter-working with other networks (IWF).

7                                              Uke Kurniawan Usman - 2005
                      GSM Network Entity
                 Home Location Register
                        ( HLR )



      Manages the mobile subscribers database


     subscriber information

     part of the mobile location information

     3 identities essential
           the International Mobile subscriber Identity
           the Mobile station ISDN Number
           the VLR address
8                                               Uke Kurniawan Usman - 2005
                        GSM Network Entity
                  Visitor Location Register
                            ( VLR )


    dynamically stores subscriber information needed to handle
    incoming/outgoing calls

    Mobile Station Roaming Number
        When a roaming mobile enters an MSC area. This MSC
    warns the associated VLR of this situation; the mobile enters
    a registration procedure through which it is assigned a
    mobile subscriber roaming number (MSRN)

    Temporary Mobile Subscriber Identity, if applicable
    The location area in which the mobile has been
      registered
    Data related to supplementary service parameters
9                                               Uke Kurniawan Usman - 2005
                 GSM Network Entity

                      AUC/EIR




     Authentication Center(s) (AUC)

     Providing the authentication key used for
     authorizing the subscriber access to the
     associated GSM PLMN.

     Equipment Identity Register(s) (EIR)

     Handling Mobile Station Equipment Identity


10                                     Uke Kurniawan Usman - 2005
     Agenda

        Network Architecture
        Functional Layer of GSM
        Air Interface
        System Capacity
        Anti Interference Technology
        Network Planning
        Numbering arrangement

11                                      Uke Kurniawan Usman - 2005
     Overview: Function Layers of GSM-1




12                          Uke Kurniawan Usman - 2005
     Protocol Stack Structure of GSM




13                         Uke Kurniawan Usman - 2005
     Agenda

     Network   Architecture
     Functional Layer of GSM
     Air Interface
     System Capacity
     Anti Interference Technology
     Network Planning
     Numbering arrangement

14                                   Uke Kurniawan Usman - 2005
       TDMA




     time

                                    Concept:
               User 3                 channel is composed of a
                                      series     of    timeslots      of
               User 2
                                      periodicity. Different signal
               User 1                 energies are distributed into
                                      different     timeslots.    The
                        Frequency
                                      adjacent channel interference
                                      is restricted by connection
     GSM adopts TDMA/FDMA mode        choosing from time to time. So
     channel width: 200KHz            the useful signal is passed
     each channel has 8 timeslots     only in the specified timeslot.



15                                          Uke Kurniawan Usman - 2005
           GSM Timeslot and Frame structure


     Frequency




       200KHz




                    BP                     time
                  15/26ms
                               interval
16                              Uke Kurniawan Usman - 2005
                         Frequency Resource


     GSM900 :                        EGSM900 :
     up: 890~915MHz                  up: 880~890MHz
     down: 935~960MHz                down: 925~935MHz
     duplex interval: 45MHz          duplex interval: 45MHz
     bandwidth: 25MHz,               bandwidth: 10MHz,
     frequency interval: 200KHz
                                     frequency interval: 200KHz
      GSM1800 :                      GSM1900MHz:
      up: 1710-1785MHz               up:1850~1910MHz
      down: 1805-1880MHz             down:1930~1990MHz
      duplex interval: 95MHz,        duplex interval: 80MHz,
      working bandwidth: 75MHz,      working bandwidth: 60MHz,
      frequency interval: 200KHz     frequency interval: 200KHz
17                                        Uke Kurniawan Usman - 2005
                      Frequency Resource

     Single Band Network              General Priority

             Which one?
                             900MHz                 High

                            1800MHz

                            1900MHz                  Low
            New Operator
                                                  Reason
      Propagation
     Characteristic
     For Operator           For Subscriber
18                                     Uke Kurniawan Usman - 2005
                    Frequency Resource


     Single Band Network

                  Single Band                      900MHz

                  Dual Band                       1800MHz



                  Triple Band                     1900MHz

     In a sense, the network determines the handsets
     can be selected.
     But nowadays, most handsets support dual
19   band.                            Uke Kurniawan Usman - 2005
                          Frequency Resource

       Single Band Network
                                                Cell coverage radius :


                  We know


     Propagation characteristic

        The higher the propagation
        frequency                                            900MHz
                                                             1800MHz
        The higher the propagation loss
                                                             1900MHz
        The smaller the cell coverage radius.

20                                              Uke Kurniawan Usman - 2005
                              Timeslot and Frame structure


                 1 super high frame = 2048 super frame = 2715648 TDMA frame

             0       1        2       3                                      2044   2045    2046     2047

                                                                                                     BCCH
                         1 super frame = 1326 TDMA frame(6.12s)                                      CCCH
SACCH/TCH                                                                                            SDCH
     FACCH   0       1        2       3                                 47   48     49          50
                 0            1                                              24            25


         1 multiplex frame = 26 TDMA frames(120ms) 1 multiplex frame = 51 TDMA frame

        0        1                    24       25           0       1                       49       50


                 1 TDMA frame = 8 timeslot(120/26 = 4.615ms)
        0        1        2       3        4        5   6       7

 21                                                                 Uke Kurniawan Usman - 2005
                   Physical Channel


       0      1     2     3     4      5        6       7

        8     9     10    11     12    13        14     15


        16    17    18    19     20    21        22     23




     The physical channel adopts FDMA and TDMA techs.
     On the time domain, a specified channel occupies the
     same timeslots in each TDMA frame, so it can be
     identified by the timeslot number and frame number.
22                                         Uke Kurniawan Usman - 2005
                 Channel Type-Summary
                                14.4Kbit/s FR TCH (TCH/F14.4)
                                9.6Kbit/s FR TCH(TCH/F9.6)
                     Data CH    4.8Kbit/s FR TCH (TCH/F4.8)


               TCH              4.8Kbit/s HR TCH (TCH/H4.8)
                                FR Voice Traffic Channel (TCH/FS)
                     Voice CH   Enhanced FR Traffic Channel (TCH/EFR)
                                HR Traffic Channel (TCH/HS)
     channel                     FCCH (down)
                                 SCH (down)
                       BCH       BCCH (down)

                                 RACH (up)
               CCH     CCCH      AGCH (down)
                                 PCH (down)
                                  SDCCH
                       DCCH       FACCH
                                  SACCH

23                                           Uke Kurniawan Usman - 2005
                           Channel Type



     Traffic Channel
       Transmit voice and data


     Signaling Channel
       transmit the signaling and synchronous data between BTS and
       MS.




24                                          Uke Kurniawan Usman - 2005
                              Channel Type


 BCH :
    Frequency Correction CHannel(FCCH)
        -- for MS error correction
    Synchronous Channel(SCH)
        -- for MS frame synchronization and BTS recognization
    Broadcasting Control CHannel(BCCH)
        -- broadcasting information(cell selection information, etc..)




25                                                  Uke Kurniawan Usman - 2005
                             Channel Type



     DCCH

     Self-help Dedicated Control Channel(SDCCH)
        for channel distribution information transmission

     Slow Associated Control Channel (SACCH)
        combined with one traffic channel or SDCCH, to transmit some
        specific information of user information

     Fast Associated Control Channel (FACCH)
        combined with one traffic channel, taking the same signal as
        SDCCH. It occupies the service channel to transmit signaling
        information.


26                                                    Uke Kurniawan Usman - 2005
     Structure of 51-frame Control CH




27                        Uke Kurniawan Usman - 2005
                   Channel Combination Type


       Several logic channels combine together in some way to form
       some specific types of channel to transmit user data or signaling
       information. They are called combined channels. One combined
       channel can be mapped to a physical channel.

       There are the following combined channels:
     a TCH/F + FACCH/F + SACCH/TF
     b TCH/H(0,1) + FACCH/H(0,1) + SACCH/TH(0,1)
     c TCH/H(0,0) + FACCH/H(0,1) + SACCH/TH(0,1) + TCH/H(1,1)
     d FCCH + SCH + BCCH + CCCH
     e FCCH + SCH + BCCH + CCCH + SDCCH/4(0...3) + SACCH/C4(0...3)
     f BCCH + CCCH
     g SDCCH/8(0 ..7) + SACCH/C8(0 .. 7)
            CCCH = PCH + RACH + AGCH
28                                                 Uke Kurniawan Usman - 2005
                 Channel Assignment inside cells




        Small capacity cell with only 1 TRX
            TN0: FCCH+SCH+CCCH+BCCH+SDCCH/4(0,_,3)+SACCH/C4(0,_,3);
            TN1-7: TCH/F+FACCH/F+SACCH/TF


        The medium-size cell with 4 TRXs
            1TN0 group: FCCH+SCH+BCCH+CCCH;
            2 SDCCH/8(0,_,7)+SACCH/C8(0,_,7);
            29 TCH/F+FACCH/F+SACCH/TF




29                                               Uke Kurniawan Usman - 2005
                Channel Assignment inside cells




        Large-size cell with 12 TRXs
         1 TN0 group: FCCH+SCH+BCCH+CCCH;
         1 TN2 group, 1 TN4 group and 1 TN6 group: BCCH+CCCH;
         5 SDCCH/8(0,_,7)+SACCH/C8(0,_,7);
         87 TCH/F+FACCH/F+SACCH/TF




30                                               Uke Kurniawan Usman - 2005
     Agenda

     Network   Architecture
     Functional Layer of GSM
     Air Interface
     System Capacity
     Anti Interference Technology
     Network Planning
     Numbering arrangement

31                                   Uke Kurniawan Usman - 2005
                           Cell Mode Layout


     Omni-directional cell

     Adopt omni-directional antenna,
     the overall directional propagation
     characteristic is the same.


     Directional cell

     In general, cell with multi-sector is in
     common use. Every directional cell
     adopts directional antenna.
32                                              Uke Kurniawan Usman - 2005
                               BTS Mode


      Capacity

     When the traffic is very low, and no possibility for quick
     increment, Omni-directional cell is used in common.
     Otherwise, we suggest to adopt the sector cell.

     Note: TRX-transceiver,each TRX handles 1 frequency.

      Coverage Area
     Sector cell is often used to enlarge the cell coverage
     radius because of the higher antenna gain.
     For special coverage ,such as road coverage, two-sector
     cell is adopted firstly.
33                                              Uke Kurniawan Usman - 2005
                        System capacity



     Erlang :

     the traffic intensity of a totally occupied channel (i.e.
     the call hour of a unit hour or the call minute of a unit
     minute). For example, the traffic of a channel occupied
     for 30 minutes in an hour is 0.5 Erlang)

     GOS:

     defined as the probability of call blocking or the
     probability when the call delay time is longer than a
     given queuing time.
34                                               Uke Kurniawan Usman - 2005
     Agenda

     Network   Architecture
     Functional Layer of GSM
     Air Interface
     System Capacity
     Anti Interference Technology
     Network Planning
     Numbering arrangement

35                               Uke Kurniawan Usman - 2005
                Reasons for Interference


       The transmission path is very complex, ranging
     from the simple line-of-sight transmission to
     encountering such terrain as buildings, hills and
     trees. Wireless channels are extremely
     unpredictable.

       Abrupt drop, or fading, of signal strength in the
     land mobile wireless channel is quite common. The
     fading feature of the mobile channel depends on the
     radio wave propagation environment.
36                                       Uke Kurniawan Usman - 2005
                      Reasons for interference


     Environmental factors:
     •   Terrain (mountains, hills, plains, water bodies, etc.);
     •   The quantity, heights, distribution and materials of
         buildings;
     •   The vegetation of the region;
     •   Weather conditions;
     •   Natural and artificial electromagnetic noises;
     •   Frequency;
     •   How MS is moved.
37                                                 Uke Kurniawan Usman - 2005
                           Interference



     Co-Channel Interference

      Conception:
                  the interference among the signals of co-
                  channel cells is called co-channel interference.
      Result from :
                  Frequency reuse
      Reduction method:
                  co-channel cells must physically be
                  spaced at a minimum interval to ensure
38                adequate isolation of transmissions. Usman - 2005
                                              Uke Kurniawan
                          Interference



      Adjacent Channel Interference
      Conception:
                  The signal interference from the frequency
                  adjacent to that of the signal used is called
                  adjacent channel interference.
      Reduction method:
                  accurate filtering and channel allocation
                  (maximizing channel intervals of the
                  cell). Interval of frequency reuse inter-cell
                  interference, such as C/I, C/A
39                                        Uke Kurniawan Usman - 2005
           Solution -Anti-interference




        FH technology
        Dynamic power control (DPC)
        Discontinuous Transceiving (DTX)
        Diversity receiving technique

40                              Uke Kurniawan Usman - 2005
               Frequency Hopping Technique


     Reason:
      counteract Rayleigh Fading
      scatter interference among multiple calls


     Types:
      Base band frequency hopping
       keeps the transmission and receiving frequency of each
       carrier unit unchanged, but merely sends FU transmission
       data to different carrier units at different FN moments.
      radio frequency hopping
       controls the frequency synthesizer of each transceiver,
       making it hop according to different schemes in different time
41     slots.
                                                   Uke Kurniawan Usman - 2005
      Discontinuous Speech Transmission (DTX)


     Two aims can be achieved by adopting DTX mode:
       •lower the total interference electric level in the air
       •save transmitter power.
           TRAU    BTS


           BTS     MS


                                        480 ms


                  comfort noise frame

                  Speech frame
42                                                Uke Kurniawan Usman - 2005
             Diversity Reception Technology


     The multi-path propagation of radio signals causes
     magnitude fading and delay time.

      Space Diversity (antenna diversity)

      Polarization Diversity
       orthogonal polarization diversity.
       horizontal polarization and vertical polarization.

      Frequency Diversity
       The working principle of this technology is that
       such fading won’t take place on the frequency
       outside the coherence bandwidth of the channel.
43                                             Uke Kurniawan Usman - 2005
     Agenda

     Network   Architecture
     Functional Layer of GSM
     Air Interface
     System Capacity
     Anti Interference Technology
     Network Planning
     Numbering arrangement

44                                   Uke Kurniawan Usman - 2005
                     Frequency Reuse




     “4 ´ 3” reuse mode:
        one group includes 3 sectors /site ,12 frequency which
        are distributed to 4 sites. Every site owns 3 frequency.


45                                          Uke Kurniawan Usman - 2005
                     Frequency Reuse




     “3 ´ 3” reuse mode:
        one group includes 3 sectors /site ,9 frequency which are
        distributed to 3 sites. Every site owns 3 frequency.


46                                         Uke Kurniawan Usman - 2005
     Agenda

     Network   Architecture
     Functional Layer of GSM
     Air Interface
     System Capacity
     Anti Interference Technology
     Network Planning
     Numbering arrangement

47                                   Uke Kurniawan Usman - 2005
                    Numbering Arrangement

 International Mobile Subscriber Identification number
                         (IMSI)

         It identifies a unique international universal number of a
         mobile subscriber, which consists of MCC+MNC+MSIN.
         1) MCC: country code, 460
         2)MNC: network code, 00 or 01
         3)MSIN: subscriber identification, H1H2H3H4
         9XXXXXX,
              H1H2H3H4: subscriber registering place
              H1H2: assigned by the P&T Administrative Bureau
         (operator )to different provinces, to each province
              H3H4: assigned by each province/city

         the IMSI of user will be written into the SIM card by
48                                                 Uke into the HLR
         specific device and software and be storedKurniawan Usman - 2005
         with other user information.
              Numbering Arrangement

     Mobile Subscriber ISDN Number(MSISDN)




         It is the subscriber number commonly
         used. China uses the TDMA independent
         numbering plan:

         CC+NDC+ H1H2H3H4 +ABC

         CC: country code, 86
         NDC: network code, 135—139, 130
         H1H2H3H4: HLR identification code
         ABCD: mobile subscriber number inside
49       each HLR                  Uke Kurniawan Usman - 2005
                Numbering Arrangement

     International Mobile Equipment Identification code
                               (IMEI)



       It will uniquely identify a mobile station. It is a
       decimal number of 15 digits. Its structure is:

       TAC+FAC+SNR+SP

       TAC=model ratification code, 6 digits
       FAC=factory assembling code, 2 digits
       SNR=sequence code, 6 digits
       SP=reserved, 1 digit

50                                       Uke Kurniawan Usman - 2005
          Numbering Arrangement

     Mobile Subscriber Roaming Number
                  (MSRN)

     The MSRN is temporarily distributed to the
     subscriber by the VLR according to the request
     by the HLR when this subscriber is called. The
     MSRN is released and can be assigned to other
     subscriber later.

         CC + NDC + 00 + M1M2M3 + ABC
         CC: country code, 86
         NDC: mobile network code, 135—139, 130
         M1M2: same as the H2H3 of MSISDN
         ABC: 000 -- 999

51                                Uke Kurniawan Usman - 2005
                 Numbering Arrangement


     Temporarily Mobile Subscriber Identification Number
                                (TMSI)



             To insure the IMSI security, the VLR will
             assign an unique TMSI number for the
             accessed subscriber. It is used locally only
             and is a 4-byte TMSI number BCD code.




52                                        Uke Kurniawan Usman - 2005

								
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